SE/30 VIA chip replacement

[croissantking]

This is a satisfying outcome. @MegaImg are you going to buy these chips?

 

[MegaImg]

Already did, Building a new Logicboard, Will try them! Almost all the IC are new, Loking for a damage board to finish it!

 

[codevonlux]

I recently worked on a SE/30 Reloaded board. The ADB chip from the donor board is bad so I used a PIC16F87 replacement ADB on this board. (mentioned here: https://68kmla.org/bb/index.php?threads/mac-se-adb-controller.38363 , with a QFN-to-PLCC adapter PCB by max1zzz).

I noticed that if I use W65C22N6TPLG-14 as VIA1 then it is not compatible with this ADB replacement, the mouse movement is sluggish then finally hung, death chime also happens from time to time during boot. Same VIA1 works fine with original ADB chip and Original 65C23 works fine with this ADB replacement.

I guess there might be some timing issue becuase it was mentioned in the ADB thread that the original 3MHz clock is not used in the PIC16F87 and it is running faster than the original ADB chip.

 

[obsolete]

Good info, thanks for posting this. Would be interesting to scope it and see what's going on.

I also had a post from macmike in a thread I started about Reloaded board troubleshooting where he mentioned issues with the WDC VIA and the RTC: https://68kmla.org/bb/index.php?threads/troubleshooting-glue-c32m-and-c16m.46886/post-530164

Figured I should link that here since this thread seems to be the knowledge base on these replacement VIAs